Pioglitazone hydrochloride (trade name ACTOS) is a drug of the family thiazolidinedione (TZD), commonly prescribed to non-insulin dependent diabetes (Type II) patients in order to decrease sensitivity to insulin resistance. TZDs act through a mechanism of peroxisome proliferator-activated receptor gamma (PPAR-γ) activation, thus influencing glucose regulated genes.

TZDs are compounds not recommended for patients with heart failure symptoms due to fluid retention and build-up which can cause or exacerbate heart problems. However, evidence supporting positive pleiotropic effects of pioglitazone on the cardiovascular system has recently been reported. Studies have highlighted beneficial effects of pioglitazone, including a reduction in blood pressure. In addition, pioglitazone can attenuate production of inflammatory and pro-atherogenic molecules in the vascular system (Schernthaner, Int J Clin Pract, 2009). Among these proteins are potent secreted factors known to exacerbate a localized inflammatory or unstabilizing response, such as Interleukin-6 (IL-6), Monocyte Chemoattractant Protein-1 (MCP-1) and Metalloproteinase-9. Data from the Schernthaner study further supported the hypothesis that pioglitazone reduces the thickness of the carotid intimal region. While the mechanisms of pioglitazone and other TZDs on the vasculature are beginning to be elucidated, much information regarding pleiotropic effects is unknown.

HemoShear's human surrogate model of the vasculature was used in the current study to understand the effects of pioglitazone at a molecular level.

The objectives of this case study were to:

• Examine the human vascular response to pioglitazone using HemoShear technology and high throughput PCR array analysis, focusing on inflammation, apoptosis, cell stress, remodeling, proliferation, and migration-related gene changes,
• Uncover the regional responses of human endothelial and smooth muscle cells in Healthy and Disease-prone areas of the arterial vasculature and highlight the importance of flow-exposure systems compared to traditional cell culture models, and
• Determine if pioglitazone influences endothelial cell permeability (i.e., enhances barrier function).

Statins, HMG-CoA reductase inhibitors, are the most widely prescribed class of drug for lipid-based cardiovascular diseases (e.g., atherosclerosis). Statins are widely prescribed to reduce systemic levels of LDL cholesterol and triglycerides, and thus have shown tremendous clinical benefit. Over the past two decades, considerable basic and clinical research has been conducted to evaluate positive off-target, or pleiotropic effects of statins. Statin therapy in humans has been shown to improve endothelial function, reduce inflammation, stabilize atherosclerotic plaques, reduce vessel remodeling, and prevent thrombus formation. While positive attributes of statins have been reported on from clinical trial data, the specific mechanism of action on human vascular cells is unknown. This is because studies of this nature cannot be performed in living humans and until now, there were no human surrogate models of the vasculature to test this.

The goal of this study was to demonstrate that HemoShear's human surrogate model of the arterial vasculature was more predictive of human clinically relevant benefits of atorvastatin relative to traditional cell culture methods. The experimental study was able to directly test the hypothesis that statins exert positive pleiotropic effects directly on the cells of the blood vessel wall.

HemoShear's technology demonstrated:

• Positive clinical correlation using the HemoShear method and opposite and confusing correlation using traditional culture methods,
• Anti-inflammatory effects of statins on endothelial and smooth muscle cells under Healthy and Disease-prone conditions,
• Attenuation of vascular remodeling and enhancement a non-proliferative, quiescent phenotype in endothelial and smooth muscle cells,
• Anti-thombotic and anti-coagulation response in BOTH endothelial and smooth muscle cell gene pathways,
• Statins may enhance endothelial barrier function (i.e. reduce permeability), and
• Additional mechanisms of action of a statin on endothelial and smooth muscle cell biology.